An even illumination of the above described type is achieved in well known apparatus by utilization of one or more light sources whose light is then rerouted by prisms. In other apparatus, the title blocks are evenly illuminated by the use of optical fibers which transmit light from the light source to the title blocks. Equal and even illumination can also be achieved by applying lacquers of different light transmissivity to the front panel or, alternatively, applying a plurality of layers of the same lacquer. This allows an even illumination of all title blocks of the front panel to be achieved even though relatively few point sources of light, for example incandescent lamps, are utilized. However, all of these known systems have various drawbacks. Prisms and optical fibers must be fastened between the light source and the title blocks in such a way that they are resistant to vibration and shock. The lacquer applied to front panels in the other systems tends to darken as time progresses, thereby preventing the desired even illumination of all title blocks.